1. Field of the Invention
The invention pertains to the art of centrifugal fan mounting arrangements and particularly to those employed in units such as furnaces and air handlers of the type typically used in residences.
2. Description of the Prior Art
Of the prior art of which applicant is aware, the closest which is disclosed in a patent is found in U.S. Pat. No. 2,464,473. The disclosure there which is material to this patent application is of a blower assembly which includes slide rails which are slidably received by horizontal track means which are connected to the horizontal partition or supporting wall. The tracks have cushioning strips secured to the surfaces which support the rails carried by the blower housing. These serve both for shock absorbing purposes as well as promoting a seal between the horizontal supporting wall and the blower housing. Additionally, both front and rear sealing strips are provided to complete the seal between the outlet of the blower housing and the horizontal supporting wall.
In addition to the noted patent, the prior art includes commercial devices in which a centrifugal fan housing is rigidly connected to a horizontal supporting plate, with the plate being slidably received into the cabinet of the furnace by tracks supported on the sides of the furnace.
In another commercial prior art arrangement the fan is provided with slide rails, the horizontal partition has tracks to receive the slide rails, and the manner of effecting an adequate air seal between the fan housing and the horizontal plate is accomplished by using several sheet metal screws which extend through the plate and into the slide rails near both the front and the rear of the furnace. By tightening the sheet metal screws the slide rails and the husing are pulled up tight enough against the plate to provide sufficiently close connection that the amount of air leakage is not undue. One disadvantage of this arrangement is that if the fan housing is to be removed for service or any other reason, there may be difficulty in getting access to the screws at the rear of the furnace because of a vertical interior wall blocking access from the front, and the possibility the furnace may be installed in a closet.
The disadvantage of the prior art arrangement in which the fan housing is more or less permanently secured to the fan plate and the plate itself is arranged to be slid into the furnace is that the assembly as a whole is relatively bulky, heavy and awkard to handle. Also, by virtue of the removability of the sliding plate, the overall rigidity of the furnace is not as great as when the fan plate is permanently fixed.
The aim of the invention is to provide a centrifugal fan mounting arrangement for a furnace or like device which is less bulky, easily removable and serviceable, and which also provides an adequate air seal between the fan housing and the fan base plate.